Boat has been running fine. Yesterday during take off I noticed it sputtering a few time during take off...almost like it was running out of fuel. Once on plane it was fine. Each take off after that it progressively gets worse. The last time I took off, I finally got it on plane and at full throttle it will do the same thing....rev up to 4800-4900 RPM's sputter down to 4500 and then back again.....very noticable. At idle it is hard to tell but doesn't seem to have any sort of miss. I was going to swap plugs today and put some fresh fuel in. Any other ideas?

Does it have a coil?

No coil, coil packs for each cylinder.

Moisture?

Had similar situation years ago...water remover solved it.

Like dry gas in the tank?

Had to be bad fuel or simply low on. Put some fresh in yesterday and no issues.

Now you need also to change all your fuel filters since you had bad gas. All the fuel filters have pick up some of the debrie / water form the bad gas. This can and will cause fuel restrictions also rust inside these filters. Lean running conditions. Also any bad gas needs to be completely drained out before putting new gas in. Bad gas loses it octane value also.

Like any motor the 496 really hates to run lean. Also test your fuel pressure with a fuel pressure gauge at idle and at full throttle. Bad gas leads to fuel problems thru out the entire fuel system not just in the gas tank. Hope this helps

Baja man do you have a fuel pressure gauge so you can see your fuel press all the time?

I do not have a gauge.

sounds like plugs are loading up ,